Agricultural tractors commonly employ a three point hitch assembly for connecting an agricultural implement to the tractor. The hitch assembly includes two laterally spaced lower draft links. The draft links are universally connected at their forward ends to the tractor. The lateral dimension between the rear ends of the draft links is controlled by the length of the agricultural implement. A power lift apparatus raises and lowers the draft links about their pivotal connection with the tractor between a lower operative position and an upper transport position.
Under some conditions, lateral or side to side sway of a farm implement relative to the tractor is desirable As an example, lateral movement of an implement may benefit tractor steering conditions such as at the end of a crop row. Under plowing conditions, where the attached implement continues to work the soil, side sway or lateral movement of the implement is particularly desirable to avoid large rocks or other obstacles in the soil. The extent of side sway or lateral movement must, however, be controlled and limited to prevent interference of the draft links with the rear wheels of the tractor.
On the other hand, there are working conditions when the implement is in its lower operative position that it is desirable to prevent lateral sway of the implement relative to the tractor. Working conditions such as planting and cultivating require that the implement follows the path of the tractor and be prevented from swaying from side-to side. Moreover, it is desirable that side sway of the implement is completely abated when the implement is raised into its transport position to provide an arrangment that is stable and safe for transporting purposes.
Various types of sway limiting devices have been proposed for use with three point hitch assemblies. Commonly used in the U.S. agricultural market are devices involving the use of removable rub blocks carried by the draft links. The rub blocks act in cooperation with fixed sway preventing means on the tractor.
Although European standards exist, agricultural implements in European markets usually vary in length according to the particular manufacturer. As such, the lateral distance between the draft links varies depending upon which implement is being used. Accordingly, multiple piece removable rub means normally used in the U. S. are not readily adaptable to the European agricultural market.
In Europe it is known to use a stabilizer assembly between the tractor and the draft link. A common stabilizer assembly includes a multi-piece telescopic structure having one piece connected to the draft link and the other piece connected to the tractor. The stabilizer operates in a free or locked condition. Depending on the design of the stabilizer assembly, when the draft links are in their lower operative position, the stabilizer assembly permits telescopic movement of the pieces relative to each other. Alternatively, the pieces of the stabilizer assembly are locked against longitudinal movement relative to one another upon rearrangement of the stabilizer assembly.
In one form, a bolt latching mechanism is used to secure the parts of the stabilizer to each other. The bolt latching mechanism consists of a pin or bolt which is movable transversely of the longitudinal axis of the telescopic structure. The bolt is guided through holes which are in alignment with one another and which are formed in the pieces of the telescopic structure. Operator intervention is required to selectively operate the stabilizer assembly in either its free condition or its locked condition.
Raising and lowering of the implement is commonly effected from a control console or panel which is readily accessible to the operator. It would be beneficial, therefore, to provide a mechanism that can be automatically locked and unlocked to prevent sway of the implement without requiring the operator to get off the tractor to perform either the locking or unlocking function for the hitch assembly.